1. Field of the Invention
The present invention relates to optical lenses for correcting anomalous color vision such as color blindness and color weakness.
2. Description of the Related Art
According to an invention disclosed in Japanese Patent No. 2813743, color blindness and color weakness correcting glasses of four kinds and 32 classes which have been capable of correcting color blindness and color weakness for a large number of cases have come to be developed by implementing correcting tests on a large number of subjects of color blindness and color weakness and by obtaining four types of color blindness and color weakness correcting spectral curves of A through D groups.
Japanese Patent Publication No. 9-503402 has also proposed a method of measuring red, green and blue spectral sensitivity curves of persons having anomalous color vision to improve the color vision by means of color filters compensating the difference from the normal spectral sensitivity curve.
However, there have been many cases in which the anomalousness of each individual is not fully improved by the lenses selected or manufactured under these methods. For instance, they allowed those persons to sense the colors from green to red such as green, yellow green, yellow, orange and red by only one color sense as green=yellow=red. Accordingly, when the brightness is the same, those persons are unable to distinguish the colors. Therefore, the further improvement of those lenses has been desired. That is, because only the person in question can sense the color blindness and weakness and has not experienced the normal color vision because they are congenital, the degree of improvement of color vision by means of the conventional color filters have been insufficient in many cases.
Then, it is an object of the invention to develop a more appropriate optical lens for correcting color vision under a new theory and to facilitate the production or selection of lenses truly suitable for each individual subject.